Key Laboratory of Marine Eco-Environmental Science and Technology, First Institute of Oceanography, Ministry of Natural Resources (MNR), Qingdao, 266061, China.
Laboratory for Marine Fisheries Science and Food Production Processes, Laoshan Laboratory, Qingdao, 266237, China.
Curr Microbiol. 2023 Sep 22;80(11):354. doi: 10.1007/s00284-023-03423-9.
Bacterial disease is one of the most critical problems in aquaculture. Probiotics represent a promising biological approach to control bacterial disease because it is effective against pathogens and environmentally friendly. This study assessed the antagonistic activities of a bacterial strain FIO1408 isolated from deep-sea water against many pathogenic bacteria in aquaculture, including Listonella anguillarum, Vibrio parahaemolyticus, Vibrio alginolyticus, Aeromonas hydrophila, Edwardsiella anguillarum, Edwardsiella tarda, and Edwardsiella piscicida. The complete genome of strain FIO1408 consisted of a circular chromosome of 4,137,639 bp and two plasmids of 16,439 bp and 24,472 bp. Phylogenetic analysis showed strain FIO1408 clustered with Bacillus velezensis strains. 12 genes/gene clusters responsible for the synthesis of secondary metabolites were identified in the FIO1408 genome, including three lipopeptides, three polyketides, three bacteriocins, one siderophore, one dipeptide, and one unknown type. Also identified were 273 unique orthologous genes primarily involved in phage resistance, protein hydrolysis, environmental survivability, and genetic stability compared to B. velezensis KACC 13105, B. velezensis FZB42, and B. velezensis NRRL B-41580. The principal safety of FIO1408 was demonstrated by genetic analyses and feeding trials. These findings will contribute to studies on the biocontrol mechanisms of B. velezensis FIO1408 and facilitate its application as a potent biological control agent against bacterial pathogens in aquaculture.
细菌病是水产养殖中最关键的问题之一。益生菌是一种很有前途的控制细菌病的生物方法，因为它对病原体有效且环保。本研究评估了从深海水中分离的细菌菌株 FIO1408 对水产养殖中许多致病性细菌的拮抗活性，包括鳗弧菌、副溶血弧菌、溶藻弧菌、嗜水气单胞菌、迟钝爱德华氏菌、迟缓爱德华氏菌和杀鲑爱德华氏菌。菌株 FIO1408 的完整基因组由一个 4137639bp 的圆形染色体和两个 16439bp 和 24472bp 的质粒组成。系统发育分析表明，菌株 FIO1408 与 Bacillus velezensis 菌株聚类。在 FIO1408 基因组中鉴定出 12 个负责合成次生代谢物的基因/基因簇，包括三种脂肽、三种聚酮、三种细菌素、一种铁载体、一种二肽和一种未知类型。还鉴定出 273 个独特的直系同源基因，这些基因主要参与噬菌体抗性、蛋白水解、环境生存能力和遗传稳定性，与 Bacillus velezensis KACC 13105、Bacillus velezensis FZB42 和 Bacillus velezensis NRRL B-41580 相比。通过遗传分析和喂养试验证明了 FIO1408 的主要安全性。这些发现将有助于研究 Bacillus velezensis FIO1408 的生物防治机制，并促进其作为一种有效的生物防治剂在水产养殖中对抗细菌病原体的应用。
